Blowpipe



a. L; WALKER.

BLOWNPE.

' APPLICATION FILED MAY I. 1919. 1,387,434. PatentedAug. 9,1921.

X v g) 7 4 o BY I A; ATTORNEYS UNITED STATES PATENT OFFICE.

GEORGE L. WALKER, OF NEW YORK, N. Y., ASSIGNOR TO AIR REDUCTION COMPANY,

' INCORPORATED, A. CORPORATION OF NEW YORK.

BLOWPIPE.

Specification of Letters Patent.

Patented Aug. 9,1921.

Application filed May 1, 1919. Serial-No. 294,004.

To all whom it may concern:

Be it known that I,.GEoRen L. WALKER, a citizen of the United States residing at New York city, in the county of New York, State of New ork, have invented certain new and useful Improvements in Blowpipes; and 1 do-hereby declare the following to be a full, clear," and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to blowpipes burning mixtures of combustible and oxidizing gases such as acetylene and oxygen and employed in heating, welding and cutting operations.

. My invention particularly relates-to the proper mixture of the gaseous constituents and particularly to prevent flashback or backward propagation of the flame in the discharge passage of the tip. Further objects and advantages of the invention will'be apparent as it is better understood, by reference to the following specification, when read in connection with the accompanyin drawing illustrating the preferred embo iments of the invention, in

which, a

Figure 1 is a lon 'tudinal section through a blowpipe head an portion of a tip;

Fig. 2 is a section on the line 2--2 of 1; ig. 3 is a rear end. elevation of the tip illustrated in Fig. 1;

Fig. 4 is a'longitudinal section through a tip illustrating-'8.- slightly diiferent form of the invention; .and

Fig. 5 is a rear end elevation of the tip as shown in Fig. 4.

It has been discovered, as ex lained in the patent to George L. Walker, 0. 1,310,099,

of the two gases supplied thereto are substantially equal or the pressure of t e acetylene slightly exceeds that of the oxygen.

In the operation of blowpipes as usually constructed any obstruction of the discharge passage results in an enrichment of the mixture in oxygen and corresponding increase .in the rate of flame propagation therein.

Usually a flashback results from this abnormal condition. In the operation of blowpipes as herein contemplated, this objectionable result is avoided. The pressures of the entering gases being substantially equal, any obstruction in the discharge passage results in a decreased flow of 'botln. gases, while the mixture remains normal, or, if the pressure of the acetylene exceeds slightly that of the oxygen, the mixture is enriched in acetylene with corresponding decrease of the rate of flame propagation in the mixture.

I have discovered that the operation of blowpipes in the manner described is materially improved when the combustible gas is conveyed through passages of uniformly diminishing cross sectional area and is mixed with the oxidizing gas immediately upon delivery from such passages. By conveying the combustible gas in this manner the maintenance of the desired velocity is assured, no opportunitybeing afi'orded for gas to expand until it flows into the discharge passage .of the tip. As a result of the operation as described, I find that the character. of the mixture produced is 1mhead and tip of a blowpipe are illustrated on an enlarged scale to more clearly distinuish the invention, 5' indicates the head aving passages 6 and 7 for. oxidizing and combustible gases which are delivered thereto through pipes 8 and 9 from a suitable source. The passage 6 terminates at the apex of a conical seat 10 in which an annular channel 11 is formed. Ducts 12 connect the channel 11 to the passage 7.

A tip 13 having a discharge passage 14 is held in assembled relation with the head 5 by a nut 14'. The tip 13 is provided at its inner end with a conical recess, the Surface of which conforms to said seat and forms therewith a gas tight joint surrounding the channel 11 and effectually preventing escape of gases from the head. One or more grooves 15 are milled, pressed or otherwise formed in the recessed surface and serve to convey the combustible gas ,from the channel 11 to the mouth of the discharge passage 14, where it mixes with the oxidizing gas from the passage 6.

In Figs. 1 and 3 it will be noted that the grooves 15 are relatively narrow and deep, being of equal width throughout, but of decreasing depth from the channel 11 to the discharge passage 14. When the tip is assembled with the head the grooves 15 form passages of uniformly diminishing cross sectional area as hereinbefore explained.

The combustible gas issues therefore fromthese passages, andis delivered to the oxidizing. gas, at maximum velocity with the resulting improvement of the mixture and other advantages.

In Figs. 4 and 5 of the drawing I have illustrated a slightly different form of my invention in which the grooves 16 are comparatively shallow.. These grooves are-of uniform depth throughout and of diminishing width from the channel 11 to the dis-.

charge passage 14. The same advantages are observed as with the previously described construction.

It is to be understood that in the accompanying drawing I have illustrated the principal modes of applying the invention, and

that changes may be made therein by varying both width and depth of the grooves or depressions to provide a tapered passage for the gas. The depth and width of the grooves may be varied and are in fact carefully proportioned to provide propermixtures in tips intended to produce flames of given dimensions. The invention is applicable, moreover, to blowpipes in which the combustible gas is conveyed to the oxidizing gas through grooves arranged otherwise than in the particular manner described, the peculiar re sults accomplished being attributable to the atlng surfaces adapted to form a gas tight joint, and a groove in oneof said surfacesforming with the cooperating surface a passage of uniformly diminishing cross sec tional area arranged to deliver combustible gas to said discharge passage.

2. In a blowpipe, the combination with a head having oxidizing andcombustible gas passages, of a tip adapted] to be assembled the combination with a therewith and provided with a discharge passage, said head having a conical seat and said tip having a corresponding surface provided with a groove forming with the cooperating surface a passage of uniformly diminishing cross sectional area arranged to deliver combustible gas to said discharge passage. 3. In a blowpipe, the combination with a head having oxidizing and combustible as passages, of a tip adapted-to be assemb ed therewith and provided with a discharge passage, said head having a projecting conical seat and said tip havinga correspondin recessed surface provided with a groove 0 uniform width and diminishing depth to provide a passage of diminishing cross section'alarea arranged to deliver (combustible gas tosaid discharge passage.

4. In a blowpipe, the combination with a head having oxidizing .and combustible gas passages, and a seat in which said passages terminate, of a tip having a discharge passage and a surface cooperating with said seat to form a gas tight joint surrounding the ends of the passages in said head, said surface having a plurality of grooves forming with the seat a passage of uniformly diminishing cross sectlonal area adapted to convey gas from one of the passages in said head to said discharge passage.

In testimony whereof I affix my signature.

GEORGE L. WALKER. 

